One of the main culprits for increased energy consumption is the growing number of information technology servers and data centres. It is a challenge faced by PowerSeraya as our business grows. The forecast was for an extra 70 servers to meet the increased business data demands. Faced by limited space and a desire to reduce energy consumption, we innovated.

PowerSeraya used virtualisation software technology with VMWare. This innovative software essentially creates virtual servers that makes multiple servers think that they are sitting on individual hardware, allowing multiple operating systems to run concurrently on a single server. This saves electricity from running fewer physical servers, and means lower cooling requirements and a reduction in office rental space. Today we have about 100 virtual servers running on 7 physical servers. This potentially results in an annual energy consumption savings of about of 75% and an avoidance of approximately 70 tons of carbon emissions per year.

Assumptions: The difference in the system utilisation of the physical servers (i.e. without virtualisation technology assumed at 7%) and the VM servers (i.e. servers using virtualisation technology, assumed at 50%) is used to work out the energy savings. The power usage of the physical server (i.e. without virtualisation) is assumed at 852 watts whereas the power usage of the VM servers (i.e. with virtualisation) is assumed to be 1,225 watts. An assumption was made that the server base load utilisation is 20%, with the remaining 80% utilisation having a linear relationship to the system utilisation. The carbon dioxide emissions avoided is calculated from the energy savings as a result of virtualisation technology. The 2006 IPPC Guidelines for the National Greenhouse Gas Inventories and the fuel mix data from the Electricity Market Company Market Report 2007 were used as a basis to calculate the carbon dioxide emissions.